FortimailApplication · Fortinet
CVE-2023-36637
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedAn improper neutralization of input during web page generation vulnerability [CWE-79] in FortiMail version 7.2.0 through 7.2.2 and before 7.0.5 allows an authenticated attacker to inject HTML tags in FortiMail's calendar via input fields.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceThis is a stored Cross-Site Scripting (XSS) vulnerability (CWE-79) in FortiMail's calendar feature. An authenticated attacker can inject malicious HTML/JavaScript into calendar input fields, which gets stored and executed when other authenticated users view the calendar.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
FortimailApplication
>= 7.0.1, <= 7.0.5= 7.2.0= 7.2.1= 7.2.2CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- Low
- User interaction
- Required
- Scope
- Changed
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Check FortiMail firmware versionLog into FortiMail web UI or CLI and locate the firmware version (typically in Dashboard > System Information or via 'get system status' command)Affected if Version is 7.0.1 through 7.0.5, or exactly 7.2.0, 7.2.1, or 7.2.2
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Verify calendar feature is activeNavigate to the calendar module in FortiMail web UI or check user role permissions for calendar accessAffected if Calendar feature is enabled and accessible to authenticated users
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Inspect calendar entries for injected scriptsIf you have administrative access, review calendar event entries for unusual HTML tags, script tags, or javascript: URIs in subject, description, or location fieldsAffected if Calendar entries contain unsanitized HTML or JavaScript code that could execute in other users' browsers
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Check recent audit logs for calendar activityReview FortiMail logs for calendar-related events, particularly from users with calendar privileges, looking for suspicious input patternsAffected if Logs show calendar entries with potentially malicious payload patterns
You are affected if FortiMail runs any version from 7.0.1 to 7.0.5, or exactly 7.2.0, 7.2.1, or 7.2.2, and the calendar feature is enabled for authenticated users.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataUpdate FortiMail to version 7.2.3 or 7.0.5 or later to receive the vendor patch. Until patched, restrict calendar feature access to trusted users and monitor for malicious payload patterns in calendar inputs.
Fix this in Fortimail
Scoped from the published advisory
- Consultation4.0 h
- Implementation8.0 h
- Testing4.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,120.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2023-36637 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2023-36637 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
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